Looking for some additional advice on the pesky radiator overflow elbow on my 300E. I had decided to use the valve stem repair idea (elsewhere in this forum) for my radiator, but discovered that I could easily remove the broken off plastic elbow section once I had removed the top radiator hose.

Having already purchased a new plastic elbow, I installed it after removing the broken piece. I also installed a new radiator cap on the expansion tank and thought the problem was fixed.

I quickly saw that coolant was escaping somehow from the expansion tank ... to the point where I need to fill it every 10 miles or so. There's not a lot of liquid under the car when I park it ... but it's kinda difficult to determine whether what's under there is from the a/c (I'm in Texas) or is coolant.

It appears to me that the plastic elbow isn't sealing correctly and that it is spurting water over the engine when I drive. Temperature stays in the 80 - 90 degree Celsius range.

I'm driving it this week (with several gallons of distilled water in the trunk) and hope to fix it this weekend. Am looking for ideas on how best to do so. Have thought of using epoxy to permanently glue the elbow into the radiator and of using the valve stem idea mentioned above. Any ideas? Pros and cons?

Thx,